spring源码学习笔记-初始化（三） registerBeanPostProcessors

refresh 方法如下：

// Register bean processors that intercept bean creation.
registerBeanPostProcessors(beanFactory);

String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

// Register BeanPostProcessorChecker that logs an info message when
// a bean is created during BeanPostProcessor instantiation, i.e. when
// a bean is not eligible for getting processed by all BeanPostProcessors.
int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));

// Separate between BeanPostProcessors that implement PriorityOrdered,
// Ordered, and the rest.
List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();
List<String> orderedPostProcessorNames = new ArrayList<String>();
List<String> nonOrderedPostProcessorNames = new ArrayList<String>();
for (String ppName : postProcessorNames) {
if (isTypeMatch(ppName, PriorityOrdered.class)) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
priorityOrderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
else if (isTypeMatch(ppName, Ordered.class)) {
orderedPostProcessorNames.add(ppName);
}
else {
nonOrderedPostProcessorNames.add(ppName);
}
}

// First, register the BeanPostProcessors that implement PriorityOrdered.
OrderComparator.sort(priorityOrderedPostProcessors);
registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

// Next, register the BeanPostProcessors that implement Ordered.
List<BeanPostProcessor> orderedPostProcessors = new ArrayList<BeanPostProcessor>();
for (String ppName : orderedPostProcessorNames) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
orderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
OrderComparator.sort(orderedPostProcessors);
registerBeanPostProcessors(beanFactory, orderedPostProcessors);

// Now, register all regular BeanPostProcessors.
List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
for (String ppName : nonOrderedPostProcessorNames) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
nonOrderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

// Finally, re-register all internal BeanPostProcessors.
OrderComparator.sort(internalPostProcessors);
registerBeanPostProcessors(beanFactory, internalPostProcessors);

beanFactory.addBeanPostProcessor(new ApplicationListenerDetector());

分析：

第1行代码通过传递过来的beanfactory查找类型为BeanPostProcessor的bean的名字；

第6行代码获得类型为BeanPostProcessor的bean数量+1+类型为beanPostProcessor的bean的长度； （+1表示下面beanProcessorChecker）

第7行代码为beanFactory注册一个BeanPostPossorChecker类，这个类的作用当一个bean没有被所有的beanPostProcessor处理后打印一行info日志。

第11行代码开始主要是区别对待继承ProiorityOrdered接口，排序并且设置；这里声明一个BeanPostProcesor的ArrayList；

第12行代码声明一个存放内部的BeanPostProcessor的List；

第13行代码声明一个存放排序BeanPostProcessor的Name的List；

第14行代码声明一个存放非排序的BeanPostProcessor的name的List；

第15行代码开始的for循环，循环BeanPostProcessor的Name，如果是匹配PriorityOrdered接口，进入if，否则如果是实习Ordered接口

执行else  if，